title: Effect of endodontic access preparation on resistance to crown-root fracture.
abstract: This investigation involved the creation of coronal-radicular fractures in vitro and compared the fracture resistance of intact human mandibular molars, with molars after varied tooth preparation. Forty freshly extracted, non-carious, nonrestored human mandibular molars were randomly divided into four treatment groups. The molars were subjected to constantly increasing occlusal load until coronal-radicular fracture occurred. Tooth preparations significantly diminished resistance to coronal-radicular fracture.
authors.affiliation: Permanente Dental Associates, Portland.
authors.forename: C A
authors.initials: CA
authors.lastname: Howe
authors.forename: D J
authors.initials: DJ
authors.lastname: McKendry
mesh_terms: D003782:Dental Pulp / Q000473:pathology; D003793:Dental Restoration, Permanent / Q000009:adverse effects; D003799:Dental Stress Analysis; D006801:Humans; D008751:Methylene Blue; D008963:Molar; D012390:Root Canal Therapy / Q000009:adverse effects; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D014172:Transillumination
chemical_list: D008751:Methylene Blue